Quick answer: most home dehumidifiers cost between about 4p and 16p an hour to run. A 250W unit running for 8 hours uses 2 kWh, which is about 53p a day at 26.32p per kWh.
Dehumidifier Running Cost Calculator
Results update as you type. Default price: 26.32p/kWh, the Ofgem cap for October to December 2026.
How dehumidifier running cost is calculated
Cost = (watts ÷ 1,000) × hours × share of time running × price per kWh
A 250W unit for 8 hours: 0.25 × 8 = 2 kWh, and 2 × 26.32p = 52.6p. Every day for a 26-week winter comes to about £95.80. Prices here use 26.32p per kWh, the Ofgem price cap unit rate for electricity paid by direct debit from 1 October to 31 December 2026. Your own rate is on your bill and may be higher or lower, especially on a fixed or Economy 7 tariff, so change it in the calculator.
Dehumidifier running costs by wattage
| Wattage | Per hour | Per 8-hour day | Per winter (26 weeks, daily) |
|---|---|---|---|
| 160W | 4.2p | 33.7p | £61.32 |
| 250W | 6.6p | 52.6p | £95.80 |
| 400W | 10.5p | 84.2p | £153.29 |
| 600W | 15.8p | £1.26 | £229.93 |
Compressor or desiccant: which costs less?
Compressor dehumidifiers work like a small fridge and are usually the cheaper type to run in a heated home. Desiccant dehumidifiers use a heated absorbent wheel, draw more power, and give off some warmth, which is useful in cold spaces where compressor units struggle. Compare the wattage on the label rather than the type alone.
How to keep the cost down
- Set the humidistat to around 50 to 60% instead of running on continuous mode.
- Close windows and doors in the room you are drying.
- Empty the tank or use the hose outlet so it does not stop and restart.
- Clean the filter regularly so air flows freely.
- Run it while drying laundry indoors, so one appliance tackles both the washing and the condensation.
Worked examples
- Drying laundry: a 160W dehumidifier running 6 hours on three washing days a week uses 0.96 kWh a session, about 25p each time or 76p a week.
- Damp room, all day: a 400W unit switched on for 24 hours with its humidistat keeping it running half the time uses 4.8 kWh, about £1.26 a day.
Frequently asked questions
How much does a dehumidifier cost to run per day?
A 250W dehumidifier running for 8 hours uses 2 kWh, which costs about 53p at 26.32p per kWh. A 160W unit costs about 34p and a 600W unit about £1.26 for the same 8 hours.
Is it expensive to run a dehumidifier 24 hours a day?
It depends on the wattage. A 250W unit running non-stop uses 6 kWh a day, about £1.58. Most units have a humidistat that pauses them once the target humidity is reached, so they rarely draw power for the full 24 hours.
Do desiccant dehumidifiers cost more to run?
Desiccant models usually draw more power than compressor models of a similar size, so they tend to cost more per hour. They work better in cold rooms such as garages and unheated bedrooms, where compressor models slow down.
Can a dehumidifier help dry clothes?
Yes. Running a dehumidifier in the room with your laundry removes the moisture the clothes give off, which speeds up drying and reduces condensation.